fixup! doc: update AUTHORS list

Author: addaleax

.mailmap

@@ -97,8 +97,9 @@ Danny Nemer <hi@dannynemer.com> <DannyNemer@users.noreply.github.com>
 Danny Nemer <hi@dannynemer.com> <hi@DannyNemer.com>
 Dave Pacheco <dap@joyent.com> <dap@cs.brown.edu>
 David Cai <davidcai1993@yahoo.com> DavidCai <davidcai1993@yahoo.com>
-David Mark Clements <david.clements@nearform.com> davidmarkclements <david.clements@nearform.com>
-David Mark Clements <david.clements@nearform.com> davidmarkclements <huperekchuno@googlemail.com>
+David Mark Clements <david.clements@nearform.com>
+David Mark Clements <david.clements@nearform.com> <huperekchuno@googlemail.com>
+David Mark Clements <david.clements@nearform.com> <david.mark.clements@gmail.com>
 David Siegel <david@artcom.de> <david.siegel@artcom.de>
 DC <dcposch@dcpos.ch> dcposch@dcpos.ch <dcposch@dcpos.ch>
 Deepjyoti Mondal <djmdeveloper060796@gmail.com>